(function () {
    const elevator = document.querySelector('.xtx-elevator');
    window.addEventListener('scroll',function () {
    const n = document.documentElement.scrollTop
    // console.log(n);  

        if (n >= 300) {
        elevator.style.opacity = '1'
        }else {
        elevator.style.opacity = '0'
        }
    })
   const backTop = document.querySelector('#backTop');
   backTop.addEventListener('click',function () {
    window.scrollTo(0,0)
   })
})();

(function () {
    const elevator =document.querySelector('.xtx-elevator-list');

    const news = document.querySelector('.xtx_goods_new');
    const popular = document.querySelector('.xtx_goods_popular');
    const brand  =document.querySelector('.xtx_goods_brand');
    const topic =document.querySelector('.xtx_goods_topic');
    elevator.addEventListener('click',function (e) {
        if(e.target.tagName === 'A'){
            const goodsName = e.target.dataset.name;
            switch(goodsName){
                case 'news':
                    window.scrollTo(0,news.offsetTop)
                    break;
                    case 'popular':
                        window.scrollTo(0,popular.offsetTop)
                        break
                        case 'brand':
                            window.scrollTo(0,brand.offsetTop)
                            break
                            case 'topic':
                                window.scrollTo(0,topic.offsetTop)
                                break
                                default:
                                    alert('Bug')
                                    
            }
        }
    })
    window.addEventListener('scroll',function () {
        const n = document.documentElement.scrollTop
        elevator.querySelector('a.active') && elevator.querySelector('a.active').classList.remove('active')
        if (n >= news.offsetTop && n < popular.offsetTop) {
            elevator.querySelector('a[data-name=news').classList.add('active')
        }else if (n >= popular.offsetTop && n < brand.offsetTop) {
            elevator.querySelector('a[data-name=popular').classList.add('active')

        }else if (n >= brand.offsetTop && n < topic.offsetTop) {
            elevator.querySelector('a[data-name=brand').classList.add('active')

        }else if (n >= topic.offsetTop) {
            elevator.querySelector('a[data-name=topic').classList.add('active')

        }
    })
})();

